EP0705722B1 - Bandage pneumatique avec profil formé d'un caoutchouc renforcé par de la silice - Google Patents

Bandage pneumatique avec profil formé d'un caoutchouc renforcé par de la silice Download PDF

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Publication number
EP0705722B1
EP0705722B1 EP95202379A EP95202379A EP0705722B1 EP 0705722 B1 EP0705722 B1 EP 0705722B1 EP 95202379 A EP95202379 A EP 95202379A EP 95202379 A EP95202379 A EP 95202379A EP 0705722 B1 EP0705722 B1 EP 0705722B1
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EP
European Patent Office
Prior art keywords
rubber
tire
tread
carbon black
base
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EP95202379A
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German (de)
English (en)
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EP0705722A1 (fr
Inventor
Bharat Kanchanlal Kansupada
Michael Julian Crawford
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Goodyear Tire and Rubber Co
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Goodyear Tire and Rubber Co
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C19/00—Tyre parts or constructions not otherwise provided for
    • B60C19/08—Electric-charge-dissipating arrangements
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
    • B29D30/00—Producing pneumatic or solid tyres or parts thereof
    • B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
    • B29D30/52—Unvulcanised treads, e.g. on used tyres; Retreading
    • B29D2030/526—Unvulcanised treads, e.g. on used tyres; Retreading the tread comprising means for discharging the electrostatic charge, e.g. conductive elements or portions having conductivity higher than the tread rubber

Definitions

  • the invention relates to a rubber tire with carbon black reinforced carcass and quantitatively silica reinforced rubber tread, said tread having a thin overcoat thereon of rubber containing a quantitative amount of electrically conductive carbon black, a coating composition therefor and a method of application.
  • the invention relates to a rubber tire with sulfur vulcanized, carbon black reinforced carcass and sulfur vulcanized tread of a cap/base construction, and particularly a cap/base-wing construction in which the tread cap is quantitatively reinforced with silica and the underlying base, or base-wing which extends over a portion of the carcass, is carbon black reinforced wherein said tread cap has a thin rubber coating on at least a portion of its outer surface which extends over at least a portion of an outer surface of said base or base-wing adjuxtapositioned to the tread cap, where said rubber coating contains a quantitative amount of electrically conductive carbon black and is sulfur-covulcanized with said tread cap and base or base-wing.
  • the invention relates to the preparation and composition of a water based coating composition therefor and an associated process of coating such a tire tread.
  • Pneumatic rubber tires are conventionally prepared with a rubber tread which can be a blend of various rubbers, typically sulfur curable, diene-based elastomers.
  • the tire rubber including its tread portion, is typically reinforced with carbon black reinforcing filler.
  • a tire is viewed as being composed of a circumferential tread and supporting carcass therefor.
  • the carcass is viewed as being composed of relatively conventional elements which include but are not limited to sidewalls, beads, innerliner and the supporting carcass plies, including fabric reinforced plies.
  • a shoulder region of a tire is considered as being a portion of the tire where its sidewall meets its tread. It is not normally a sharp line of demarkation and its actual position may vary somewhat from tire to tire.
  • the bead portion of the carcass is typically composed of a relatively inextensible bundle of wires which is encased in carbon black reinforced rubber and is designed to contact a metal rim on which the tire itself is mounted to form a tire/rim, or tire/wheel, assembly which itself conventionally adapted to be mounted on a vehicle.
  • the rim is typically steel or aluminum, or alloy thereof, and is thus electrically conductive since the metal is considered as having a very low resistance to flow of electricity.
  • the term metal as used herein for the metal rim is intended to be electrically conductive metals such as the aforesaid steel and aluminum rims as would be understood by those having skill in such art.
  • carbon black reinforced rubber components such as for example chippers and chaffers may be positioned in the bead area of the tire construction to assist in cushioning the bead component against the metal rim.
  • a reference to the aforesaid bead component of the tire carcass is intended to include such other rubber components unless otherwise indicated.
  • Rubber by itself is generally considered as being a substantial electrical insulator or, in other words, a rather poor conductor of electricity.
  • a carbon black reinforced rubber vehicular tire while still providing a degree of resistance to flow of electricity, has a considerably higher electrical conductivity, or lower resistance to flow of electricity, than rubber without the carbon black reinforcement.
  • potential electrical energy which may be created by components of or within a moving vehicle as its tires, or tire/wheel assemblies, are rotating and traveling over the ground, is dissipated from the rim of a tire/rim assembly to the ground via the carbon black reinforced rubber path of the tire carcass and tread, which is understood herein to be primarily the outer rubber surface of the tire.
  • the carbon black reinforced rubber of the tire carcass and associated tread normally provide a continuous path to dissipate electrical energy and thereby retard or eliminate static electrical charge from building up and/or accumulating under dynamic conditions of a rotating tire on a vehicle traveling across the ground.
  • electrically conductive carbon blacks are those which, when blended in amount of 50 phr with a diene-based elastomer such as, for example emulsion polymerization prepared styrene/butadiene copolymer, and the resulting mixture sulfur cured, provide a composition demonstrating a surface electrical resistance of 10,000 ohms or less according to ASTM D257-66, Mod G, as hereinafter described.
  • a diene-based elastomer such as, for example emulsion polymerization prepared styrene/butadiene copolymer
  • carbon black reinforced rubber tires may sometimes be prepared which have outer rubber treads designed to be ground contacting which are quantitatively reinforced with silica and thus contain only minimal amounts such as for example 10 phr or less of carbon black.
  • silica reinforced tire tread construction although the various other rubber components of the tire, namely the aforesaid tire carcass, are quantitatively reinforced with carbon black and thus have a degree of electrical conductivity, the silica reinforced tread itself has a substantially lower electrical conductivity, or in other words a substantially higher electrical resistance and thus create a degree of electrical insulating effect between the tire carcass and ground.
  • Such a tire construction has a substantially less tendency to dissipate static electricity from the tire to the ground, and particularly from the metal rim of a tire/rim assembly to the outer surface of the tire tread and thence to the ground, which may be generated by a dynamic condition of the rotation of the tire on a moving vehicle. Accordingly, a potential for static electricity to build up, or increase, is considered to be higher for such a tire construction than for a similar tire with a carbon black reinforced tread.
  • Such a coating is highly desirable for such a coating to be applied as a water based, film forming carbon black containing rubber composition.
  • the film coating be film forming in nature as it is applied to the rubber surface, it is envisioned that it forms a substantially continuous film on the tread surface and ultimately the surfaces of the grooves therein. It is also desirable that the coating adequately adheres to the tire tread surface, ultimately its groove walls.
  • the grooves communicate with the carbon black reinforced rubber shoulder of the tire, the area of the tire where the sidewall and tread meet, in order for the coating to communicate with the carbon black reinforced rubber portion of the tire, namely the tire carcass and the tread base in a tread cap/base construction.
  • the cap is substantially silica reinforced and its base is substantially carbon black reinforced.
  • the rubber coating (i) contains a quantitative amount of electrically conductive carbon black for dissipation of electrical energy under the aforesaid conditions, (ii) is covulcanized with the rubber tire tread in order that it be integral with the tread and the walls of grooves of a tire tread configuration composed of lugs and grooves (iii) be extremely thin so that it does not appreciably increase the volume of the tire and does not appreciably affect the tread properties of the tread and (iv) be applicable as a water based composition with a suitably short drying time in order to be practical in a manufacturing process.
  • the coating should contain a sufficient amount of the carbon black to suitably dissipate an electrical charge although it is believed that too high of a carbon black concentration in the rubber coat would cause the coat to excessively crack on the rubber surface and thus interfere with a continuous coating film aspect.
  • the thinness of the coating is important to not add to the volume of the tire in its vulcanization mold and to not detract appreciably from the tire's tread properties. Indeed, in one aspect, it is expected that the film will wear off of the outer surface of tire tread lugs during use of the tire.
  • the coating composition should be composed of a blend of (i) one or more of aqueous rubber emulsions having a basic pH selected from emulsion polymerization prepared synthetic rubber(s) and natural rubber latex and (ii) a water dispersion of carbon black having a basic pH.
  • a basic pH would normally be expected for the aforesaid synthetic and natural rubber emulsions and is highly desirable and perhaps necessary for the carbon black dispersion in order that an addition of the carbon black dispersion to the latex not pre-precipitate or cause a coagulation of the rubber from the emulsion.
  • the water based coating composition wet the surface of the rubber to be coated and form a continuous film thereon upon drying.
  • wetting agents and perhaps a thickening agent, defoamer, preservative and biocide might be added to the basic coating composition.
  • the terms "quantitatively reinforced with silica”, “quantitative silica reinforced rubber” and the like which may be used in conjunction with rubber tire treads refer to such rubber treads which contain silica in a range of 40 to 90 phr and, optionally, carbon black reinforcing filler in an amount of up to about 10 phr.
  • a water-based rubber composition which comprises a blend of (A) at least one latex selected from aqueous emulsion polymerization prepared styrene/butadiene copolymer rubber latex, emulsion polymerization prepared polybutadiene latex and natural cis 1,4-polyisoprene latex, and (B) an aqueous dispersion of electrically conductive carbon black, wherein said carbon black is present therein in an amount of 25 to 200, preferably 40 to 100, phr and where said rubber/carbon black composition, when dried and sulfur cured, is characterized by having a surface resistivity of less than 10,000 ohms according to ASTM Test D257-66, Mod. G.
  • the water-based rubber composition may comprise a blend of (A) at least one aqueous styrene/butadiene copolymer rubber latex having a pH in a range of 8.5 to 12.5 and a rubber concentration of 50 to 75, sometimes preferably 65 to 75, percent therein and bound styrene in the rubber of 23 to 35 percent and a natural cis 1,4-polyisoprene rubber latex with a pH in a range of 9 to 11 and a rubber concentration of 50 to 70 weight percent therein, and, optionally, an additional emulsion polymerization prepared polybutadiene latex having a pH in a range of 8 to 10 and a rubber concentration in a range of 40 to 60 weight percent therein, and (B) an aqueous dispersion of electrically conductive carbon black having a pH in a range of 8 to 10 with a carbon black dispersion of 20 to 30 weight percent therein, wherein said carbon black is present in an aqueous styren
  • an important and significant essence of this invention is the creation and application to a silica reinforced rubber tire tread of a water based coating composition comprised of (i) a rubber latex and (ii) a water dispersion of an electrically conductive carbon black.
  • styrene/butadiene latices are conventionally manufactured with rubber concentrations on an order of 20 to 35 weight percent elastomer. It is understood that concentrated styrene/butadiene latices containing the required 60 to 72 weight percent elastomer are only practically prepared by fractionating or otherwise removing a portion of the water of the latex to increase the rubber concentration, and thus reduce its water concentration. It is understood that such latices with the substantial higher elastomer content are more conventionally used, for example, in the commercial preparation of foam rubber products.
  • emulsion polymerization prepared polybutadiene latex having a conventional rubber content of 40 to 50 weight percent, or even up to 60 percent if available, of the elastomer is too dilute to be quantitatively practically useful in this invention unless it is used as an additive, or in addition, to the other latices for the coating composition or unless the concentration thereof in the latex is increased to above 60 percent unless the coating is applied to a hot rubber surface and/or external heating is applied.
  • wetting agent it is considered important to add a wetting agent to facilitate a wetting of the unvulcanized rubber surface by the water based rubber coating composition.
  • a wetting agent usually 1 to 3 phr of a wetting agent is used depending somewhat upon the composition of the unvulcanized rubber surface, including its oil content.
  • rubber surface compositions containing higher concentrations of rubber processing oil use water based rubber coating compositions with higher concentrations of wetting agents in order to effectively wet the rubber surface.
  • wetting agents is understood to be understood known to those having skill in the coating art.
  • latex is used herein to indicate that the rubber emulsions are used as they have been produced or recovered without re-dissolving and re-emulsifying from a dry rubber.
  • this electrical resistivity value is substantially lower than normal carbon black reinforced rubber compositions conventionally used for tire treads. It is therefore considered necessary to use electrically conductive carbon blacks for such purpose which will produce the aforesaid surface electrical resistivity of less that 10,000 ohms according to the ASTM Test D257-66, Mod G when mixed with sulfur curable rubber in an amount of 50 phr of carbon black and the rubber composition sulfur cured.
  • This maximum electrical resistivity for the cured coating is considered significant because the thin coating layer on the walls of the grooves of the tire tread is intended to be relied upon after the coating in the outer surface of the tread lugs has worn away.
  • such a rubber coating composition is considered herein to be desirable in many respects for a silica reinforced rubber tire tread composition which itself may have an electrical resistivity in a range of at least 1,000,000,000 ohms according to said ASTM Test D257-66, Mod. G in order to provide a designed path for suitable electrical leakage, or dissipation, from the tire to the road.
  • method of preparing a rubber tire tread comprises the steps of (A) applying a coating of the water-based composition of this invention to an outer surface of a cap of an unvulcanized, sulfur curable rubber tire tread of a cap/base construction in a manner that the said coating also extends over and covers a portion of an outer surface of the underlying tread base adjuxtapositioned to the said outer surface of the tread cap and (B) drying said coating; wherein said cap rubber contains 40 to 90 phr of silica and up to 10 phr of carbon black and said underlying base rubber contains, for example 30 to 50 phr of carbon black and is thereby said to be carbon black reinforced.
  • a pneumatic rubber tire composed of (i) an outer, circumferential sulfur vulcanized rubber tread component configured with lugs and grooves which contains quantitative silica reinforcement in an amount of 40 to 90 phr and less than 10 phr of carbon black and (ii) a carcass component which is comprised of sulfur vulcanized carbon black reinforced rubber components containing at least 40 phr of carbon black
  • such a method of preparing a tire where said tread is of a cap/base-wing construction where the wing of the said base extends laterally outward from the base and radially inward over the sidewall portion of the carcass of the tire and where said coating extends over and covers at least a portion of an outer surface of said base-wing adjuxtapositioned to the said outer surface of the said tread cap and is exclusive of the innerface between the tread base-wing and the tire carcass sidewall.
  • the thin, dried and covulcanized coating of this invention has a thickness on the tire surface of less than 0.005 cm.
  • covulcanized it is meant that the coating composition is vulcanized together with the tire and thereby becomes integral therewith as opposed to being a simple laminate.
  • the co-vulcanization may normally occur by autogenous vulcanization of the thin coating, after it is dried, via the free sulfur on the surface of the tire.
  • curatives may be added to the coating composition as a water based dispersion thereof which may include sulfur cure accelerator(s) and/or sulfur.
  • the water based rubber composition of this invention can be suitably prepared, for example, by the steps of blending the latex, or latices, with the water dispersion of carbon black.
  • E-SBR emulsion polymerization prepared E-SBR, it is meant that styrene and 1,3-butadiene are copolymerized as an aqueous emulsion. Such are well known to those skilled in such art.
  • the emulsion polymerization prepared styrene/butadiene copolymer rubber (E-SBR) to have a medium to relatively low styrene content in a range, for example, of 23 to 35 percent bound styrene.
  • the cis 1,4-polyisoprene natural rubber is well known to those having skill in the rubber art.
  • the carbon black reinforced overcoat for the quantitative silica reinforced rubber tread can be suitably applied to the tread, for example, by spraying or brushing.
  • Tire assembly is vulcanized in a suitable mold under conditions of elevated temperature, eg. in a range of 150 to 180°C.
  • a tire construction 1 is provided with a circumferential tread component composed of a tread cap 2 and tread base 6 construction in which the tread base 6 has a wing extension 17 which may be referred to herein as a base-wing.
  • the tire has a carcass 3 which is composed of beads 5 encased with carbon black rubber, carbon black reinforced sidewalls 4 and supporting carcass plies 10 and belt 11.
  • the rubber tread cap 2 contains a quantitative amount of silica, namely about 65 phr, and a minimal amount of carbon black, namely about 6 phr.
  • the rubber tread base 6 and associated wing 17, if present, is carbon black reinforced with at least 40 phr of carbon black as is the sidewall rubber 4 and rubber for the bead 5.
  • a water based coating 7 containing an electrically conductive carbon black in an amount of 50 phr is applied to the surface of the tread cap 2 which extends over a portion of the outer surface of the tread base 6 or tread base-wing 17. If the tread is being pre-coated prior to being built onto a tire carcass, the coating 7 extends to a region on the tread base 6 or base-wing 17 which is exclusive of the surface thereof which is to be applied to the tire carcass.
  • the coating 7 is dried and the assembly of coated tread and carcass is vulcanized to form a tire with a tread configuration 18 having lugs 12 and grooves 13 with the covulcanized coating 7 being thereby integral with the walls and bottom of the grooves 13 and outer surface of the lugs 12. Indeed the coating thereon communicates directly with the shoulder region, and thereby the tread base or base-wing, as the case may be, to form an electrically conductive path from the tread to the bead area of the tire.
  • the coating 7 is worn away from the outer surface of the tread lugs 12 to leave the lugs 20 with associated grooves 13 which contain the covulcanized coating 7 on their walls and bottoms.
  • the coating 7 may be applied to an extruded, unvulcanized tread stock 14, 15 or 16 after which the coated tread stock is built into the tire construction 1 following which the assembly is vulcanized under conditions of elevated temperature and pressure to form a vulcanized tire.
  • the coating 7 is applied as the aforesaid aqueous based composition and dried following which the assembly is vulcanized under suitable vulcanization conditions and the dried coating 7 becomes covulcanized with the outer surface of the tread 2 of the tire construction.
  • the carbon black for the coating 7 be an electrical conductive type of carbon black.
  • the coating is exclusive of the portion of the rubber extrusion which will come in contact with other portions of the tire construction when the tread stock is built into the tire construction. This aspect is to prevent the coating from interfering with adhesion of the various components to the tread upon vulcanizing the tire construction.
  • the tire construction with the coated tread stock, is shaped and vulcanized in a suitable mold to form a tire having a tread configured with what is referred to herein lugs and grooves.
  • the said coating which becomes covulcanized with the tire, covers the outer surface of the lugs and the walls and bottoms of the grooves and extends to the carbon black reinforced rubber of the said wings which are now located in the shoulder region of the tire between the tread and sidewalls.
  • sulfur vulcanizable elastomers are contemplated for the tread, including its cap and base, or base-wing, as well as the carcass rubber with which the tread base, or base-wing contacts. While selection of the rubber is not considered critical for the basic operation of this invention, diene-based elastomers are directly contemplated with their carbon-to-carbon double bonds being available for sulfur curing, or vulcanization.
  • sulfur curable elastomers for such use, but illustrated here only as examples which are not intended to be exhaustive, are natural cis 1,4-polyisoprene rubber and synthetic polymers and copolymers of dienes such as isoprene and butadiene, including polyisoprene, polybutadiene and isoprene/butadiene copolymers and copolymers thereof with aromatic vinyl compounds such as, for example, styrene and alpha methyl styrene representative of which are styrene/butadiene copolymers, whether prepared by organic solution or by aqueous emulsion polymerization.
  • Such elastomers are known for use in the preparation of tires.
  • silica The commonly employed siliceous pigments used in rubber compounding applications are usually precipitated siliceous pigments (referred to herein as silica).
  • the siliceous pigments employed may be precipitated silicas such as, for example, those obtained by the acidification of a soluble silicate, e.g., sodium silicate.
  • the BET surface area of the silica may, for example, be a range of 50 to 300, alternatively 120 to 200, square meters per gram. A BET method of measuring surface area is described in the Journal of the American Chemical Society, Volume 60, page 304 (1930) .
  • the silica may also have a dibutylphthalate (DBP) absorption value, for example, in a range of 100 to 400, and usually, as it is understood, 150 to 300.
  • DBP dibutylphthalate
  • silicas may be considered for use in this invention such as, for example only and without limitation, silicas commercially available from PPG Industries under the Hi-Sil trademark with designations 210, 243, etc; silicas available from Rhone-Poulenc, with designations of Z1165MP and Z165GR and silicas available from Degussa AG with, for example, designations VN2 and VN3, etc.
  • silica is conventionally used with a coupling agent, or what is sometimes referred to as a reinforcing agent.
  • coupling agents capable of reacting with both the silica surface and the rubber elastomer molecule, in a manner to cause the silica to have a reinforcing effect on the rubber
  • Such coupling agents may be premixed, or pre-reacted, with the silica particles or added to the rubber mix during the rubber/silica processing, or mixing, stage. If the coupling agent and silica are added separately to the rubber mix during the rubber/silica mixing, or processing stage, it is considered that the coupling agent then combines in situ with the silica.
  • such coupling agents may, for example, be composed of a silane which has a constituent component, or moiety, (the silane portion) capable of reacting with the silica surface and, also, a constituent component, or moiety, capable of reacting with the rubber, particularly a sulfur vulcanizable rubber which contains carbon-to-carbon double bonds, or unsaturation.
  • the coupler acts as a connecting bridge between the silica and the rubber and thereby enhances the rubber reinforcement aspect of the silica.
  • the silane of the coupling agent apparently forms a bond to the silica surface, possibly through hydrolysis, and the rubber reactive component of the coupling agent combines with the rubber itself.
  • coupling agents are taught for use in combining silica and rubber, such as for example, silane coupling agents containing a polysulfide component, or structure, such as bis-(3-triethoxysilylpropyl) tetrasulfide.
  • the rubber composition of the tread rubber as well as the carcass rubbers would be compounded by methods generally known in the rubber compounding art, such as mixing the various sulfur-vulcanizable constituent rubbers with various commonly used additive materials such as, for example, curing aids, such as sulfur, activators, retarders and accelerators, processing additives, such as oils, resins including tackifying resins, silicas, and plasticizers, fillers, pigments, fatty acid, zinc oxide, waxes, antioxidants and antiozonants, peptizing agents and reinforcing materials such as, for example, carbon black.
  • curing aids such as sulfur, activators, retarders and accelerators
  • processing additives such as oils, resins including tackifying resins, silicas, and plasticizers
  • fillers, pigments, fatty acid, zinc oxide, waxes, antioxidants and antiozonants peptizing agents and reinforcing materials such as, for example, carbon black.
  • peptizing agents and reinforcing materials such as,
  • Typical amounts of tackifier resins although not expected to be used in the tread rubber utilized in the practice of this invention, may comprise 0.5 to 10 phr, usually 1 to 5 phr.
  • Typical amounts of processing aids comprise 1 to 50 phr. Such processing aids can include, for example, aromatic, napthenic, and/or paraffinic processing oils.
  • Typical amounts of antioxidants comprise 1 to 5 phr. Representative antioxidants may be, for example, diphenyl-p-phenylenediamine and others, such as, for example, those disclosed in the Vanderbilt Rubber Handbook (1978), pages 344-346 .
  • Typical amounts of antiozonants comprise 1 to 5 phr.
  • Typical amounts of zinc oxide comprise 2 to 5 phr.
  • Typical amounts of waxes comprise 1 to 5 phr. Often microcrystalline waxes are used.
  • peptizers if used, would be expected to comprise 0.1 to 0.3 phr.
  • Typical peptizers may be, for example, pentachlorothiophenol and dibenzamidodiphenyl disulfide.
  • Vulcanization of rubber in general terms is often conducted in the presence of a sulfur vulcanizing agent.
  • suitable sulfur vulcanizing agents include elemental sulfur (free sulfur) or sulfur donating vulcanizing agents, for example, an amine disulfide, polymeric polysulfide or sulfur olefin adducts.
  • the sulfur vulcanizing agent is elemental sulfur.
  • sulfur vulcanizing agents are generally used for sulfur vulcanizable rubber compositions in an amount ranging from 0.5 to 4 phr, or even, in some circumstances, up to 8 phr, with a range of from 1.5 to 2.5, sometimes from 2 to 2.5, being preferred.
  • Accelerators are generally used for many sulfur vulcanizable rubber compositions to control the time and/or temperature required for vulcanization and to improve the properties of the vulcanizate. Retarders might also be used to control a rate of vulcanization.
  • a single accelerator system may be used, i.e., primary accelerator.
  • a primary accelerator(s) is used in total amounts ranging, for example, of from 0.5 to 4, preferably 0.8 to 1.5, phr.
  • combinations of a primary and a secondary accelerator might be used, with the secondary accelerator being used in amounts of 0.05 to 3 phr, for example, in order to activate and to improve the properties of the vulcanizate.
  • Combinations of these accelerators might be expected to produce a synergistic effect on the final properties and are somewhat better than those produced by use of either accelerator alone.
  • delayed action accelerators might sometimes be used which are not affected by normal processing temperatures but produce a satisfactory cure at ordinary vulcanization temperatures.
  • Suitable types of accelerators that may be used in the present invention are amines, disulfides, guanidines, thioureas, thiazoles, thiurams, sulfenamides, dithiocarbamates and xanthates.
  • the primary accelerator is a sulfenamide.
  • the secondary accelerator is preferably a guanidine, dithiocarbamate or thiuram compound.
  • the tire can be built, shaped, molded and cured by various methods which will be readily apparent to those having skill in such art.
  • a modified ASTM Method D257-66 is used for measuring surface resistivity of rubber compositions which contain carbon black and/or silica.
  • the modification of the ASTM procedure used herein consisted essentially of modifying the voltage of the ASTM method by reducing it from 500 volts to 0.1 volts to accommodate a measurement of the very low surface resistivity of coated rubber samples.
  • This modified ASTM method is referred to herein as ASTM D257-66, Mod. G.
  • the Mod. G is not an official ASTM designation, has not been submitted to any ASTM committee for review and only refers to the aforesaid modification as used herein.
  • discs of vulcanized rubber compositions having a diameter of 10.2 cm and a thickness of about 0.2 cm, with the thickness being slightly greater, namely 0.002 to 0.005 cm greater, for the coated discs to be prepared as hereinafter described.
  • Rubber compositions were prepared with carbon black reinforcement and with silica reinforcement.
  • the ingredients for the compositions were mixed in two stages, namely a first stage for the basic ingredients followed by a second stage for the curatives.
  • Such mixing procedure is well known to those having skill in the rubber mixing art.
  • the ingredients were mixed in a rubber mixer for about 3 minutes to a temperature of about 160-170°C. Following the mixture was removed from the mixer and allowed to cool to about 25°C.
  • the second stage the mixture, together with curative ingredients where then mixed in a rubber mixer for about 1.5 minutes to a temperature of about 110°C after which the final mixture, or composition, was removed from the mixer and allowed to cool to about 25°C.
  • composition Exp X for the carbon black reinforced rubber
  • composition Exp Y for the silica reinforced rubber.
  • the respective compositions were comprised of the materials as shown in the following TABLE I .
  • Water based rubber compositions containing electrically conductive carbon black were prepared which contained quantitative amounts of electrically conductive carbon black.
  • the water based compositions were prepared by blending aqueous latex emulsions with a water dispersion of electrically conductive carbon black.
  • the coated discs were vulcanized at a temperature of about 150°C for about 18 minutes. It is considered herein that the coatings co-vulcanized with the compositions. The coatings were considered to have an estimated a thickness of 0.002 to 0.005 cm.
  • the water based rubber coating compositions containing the electrically conductive carbon black were comprised of the materials, or ingredients, shown in the following Table 2. About one phr of a wetting agent was used in the formulation as Surfynol 465 epoxylated tetramethyldecynediol from Air Products.
  • ASTM D257-66, Mod. G. uses the prescribed voltage of 0.1 volts.
  • these examples demonstrate a suitable electrical path can be formed on a relatively insulative silica reinforced rubber surface by application of the coating used in this invention composed of a blend of rubber latex and electrically conductive carbon black. It is further considered that these examples demonstrate that such a coating can be applied, with a suitable drying time, in the preparation of tire with tread composed of an insulative silica reinforced rubber to create a suitable electrical path for dissipating electrical energy from the tire to the ground.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Tires In General (AREA)
  • Compositions Of Macromolecular Compounds (AREA)
  • Tyre Moulding (AREA)
  • Coating Of Shaped Articles Made Of Macromolecular Substances (AREA)

Claims (7)

  1. Composition de caoutchouc à base d'eau, caractérisée par le fait qu'elle comprend un mélange de (A) au moins un latex de caoutchouc aqueux choisi parmi un latex de caoutchouc de copolymère de styrène/butadiène préparé par polymérisation en émulsion, un latex de polybutadiène préparé par polymérisation en émulsion et un latex de caoutchouc naturel de cis-1,4-polyisoprène, et de (B) une dispersion aqueuse de noir de carbone électriquement conducteur, dans laquelle ledit noir de carbone est présent en une quantité de 25 à 200 phr et dans laquelle ladite composition de caoutchouc/noir de carbone, après séchage et vulcanisation au soufre, possède une résistivité superficielle inférieure à environ 10.000 ohms selon la norme ASTM D257-66, modèle G.
  2. Procédé de préparation d'une bande de roulement de bandage pneumatique en caoutchouc, caractérisé par le fait qu'il comprend les étapes consistant à: (A) appliquer un revêtement (7) sur la composition à base d'eau selon la revendication 1 sur une surface externe d'un recouvrement (2) d'une bande de roulement de bandage pneumatique en caoutchouc vulcanisable au soufre, non vulcanisée, dont la structure est du type à recouvrement/base (2, 6) de telle sorte que ledit revêtement s'étend également par-dessus et recouvre au moins une portion d'une surface externe de la base de bande de roulement sous-jacente juxtaposée à la surface externe dudit recouvrement de bande de roulement (2), et (B) sécher ledit revêtement; dans lequel ledit caoutchouc de recouvrement contient de 40 à 90 phr de silice et jusqu'à 10 phr de noir de carbone, et ledit caoutchouc de la base sous-jacente contient de 40 à 60 phr de noir de carbone.
  3. Procédé de préparation d'un bandage pneumatique (1), caractérisé par le fait qu'il comprend le montage de la bande de roulement du bandage pneumatique en caoutchouc possédant une structure du type à recouvrement/base (2,6) préparé conformément à la revendication 2, sur une carcasse de bandage pneumatique renforcé avec du noir de carbone, contenant au moins 40 phr de noir de carbone, dans lequel le caoutchouc dudit recouvrement de bande de roulement (2) contient de 10 à 90 phr de silice et jusqu'à environ 10 phr de noir de carbone, et le caoutchouc de ladite base de bande de roulement et de ladite carcasse du bandage pneumatique contient de 40 à 60 phr de noir de carbone.
  4. Procédé de préparation d'un bandage pneumatique (1), caractérisé par le fait de monter une bande de roulement de bandage pneumatique en caoutchouc, dont la structure est du type à recouvrement/base (2, 6), sur une carcasse de bandage pneumatique en caoutchouc (3), à la suite de quoi, ladite bande de roulement de bandage pneumatique est enduite conformément au procédé de la revendication 2; dans lequel le caoutchouc dudit recouvrement de bande de roulement (2) contient de 40 à 90 phr de silice et jusqu'à environ 10 phr de noir de carbone, et le caoutchouc de ladite base de bande de roulement (6) et de la carcasse (3) du bandage pneumatique contient au moins 40 phr de noir de carbone.
  5. Procédé de préparation d'un bandage pneumatique (1), caractérisé par le fait de monter une structure de bandage pneumatique munie d'une bande de roulement d'un bandage pneumatique enduite conformément au procédé selon la revendication 3 ou 4 et le fait de mouler et de vulcaniser ladite structure de bandage pneumatique enduite dans un moule approprié pour obtenir un bandage pneumatique comportant une bande de roulement configurée avec des côtes (12) et des rainures associées (13), ledit revêtement (7) étant soumis à une covulcanisation et s'étendant par-dessus la surface externe desdites côtes et par-dessus les surfaces des parois et des fonds desdites rainures, dans lequel ledit revêtement s'étend jusqu'à et vient se mettre en contact avec une portion dudit caoutchouc de la base de la bande de roulement (6) et/ou de la carcasse (3) du bandage pneumatique, renforcé avec du noir de carbone, et dans lequel ledit revêtement possède une épaisseur inférieure à environ 0,005 cm.
  6. Procédé de préparation d'une bande de roulement selon la revendication 2, caractérisé en ce que ladite bande de roulement possède une structure du type à recouvrement/aile de base, dans lequel l'aile (17) de ladite base représente un prolongement latéral de la base (6) et dans lequel ledit revêtement (7) s'étend par-dessus et recouvre au moins une portion d'une surface externe de ladite aile de base (17) juxtaposée à ladite surface externe dudit recouvrement (2) de la bande de roulement.
  7. Procédé de préparation d'un bandage pneumatique (1) selon la revendication 3, 4 ou 5, caractérisé en ce que ladite bande de roulement possède une structure de type recouvrement/aile de base, dans laquelle l'aile (17) de ladite base (6) s'étend latéralement à l'extérieur de la base et en direction radiale vers l'intérieur par-dessus la portion de flanc de la carcasse (3) du bandage pneumatique et dans lequel ledit revêtement (7) s'étend par-dessus et recouvre au moins une portion d'une surface externe de ladite aile de base (17) juxtaposée à ladite surface externe dudit recouvrement (2) de la bande de roulement et est exclu de la face interne entre la base de bande de roulement, l'aile de base et le flanc (4) de la carcasse du bandage pneumatique.
EP95202379A 1994-09-13 1995-09-04 Bandage pneumatique avec profil formé d'un caoutchouc renforcé par de la silice Expired - Lifetime EP0705722B1 (fr)

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US30500594A 1994-09-13 1994-09-13
US305005 1994-09-13

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EP0705722B1 true EP0705722B1 (fr) 1998-11-25

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EP (1) EP0705722B1 (fr)
JP (1) JP3542420B2 (fr)
KR (1) KR100348228B1 (fr)
AU (1) AU714173B2 (fr)
BR (1) BR9503945A (fr)
CA (1) CA2138726A1 (fr)
DE (1) DE69506207T2 (fr)
ES (1) ES2126207T3 (fr)
TR (1) TR199501095A2 (fr)
ZA (1) ZA957282B (fr)

Families Citing this family (36)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4447823B4 (de) * 1994-12-21 2007-07-26 Dunlop Gmbh Fahrzeugreifen und Verfahren zu seiner Herstellung
EP0718126B1 (fr) * 1994-12-22 1999-11-03 Sumitomo Rubber Industries Limited Bandage pneumatique ayant des propriétés de décharge électrostatique
CA2173917A1 (fr) * 1995-07-20 1997-01-21 Manuela Pompei Pneu a bande de roulement en caoutchouc arme de silice et membrane en caoutchouc renforce au noir de carbone
EP0798142B1 (fr) * 1996-03-29 1998-03-04 Continental Aktiengesellschaft Bandage pneumatique pour véhicule
DE19625091A1 (de) * 1996-06-24 1998-01-02 Rhein Chemie Rheinau Gmbh Verhinderung der elektrostatischen Aufladung von Luftreifen
EP0819741A3 (fr) * 1996-07-16 1998-10-21 Bridgestone Corporation Solution de caoutchouc conducteur de l'électricité et son utilisation dans les pneumatiques
US6415833B1 (en) 1996-07-18 2002-07-09 Bridgestone Corporation Pneumatic tire having electrically conductive rubber layer in land portion defined between circumferential grooves
US5898047A (en) * 1996-09-23 1999-04-27 The Goodyear Tire & Rubber Company Tire with outer carbon black reinforced rubber strip for static reduction
DE69717958T2 (de) 1996-10-17 2003-04-30 Sumitomo Rubber Ind Luftreifen
CA2209740A1 (fr) * 1997-01-13 1998-07-13 Manuela Pompei Pneumatique a bande de roulement en caoutchouc renforce de silice et comportant une bande conductrice en caoutchouc
IT1291210B1 (it) 1997-03-18 1998-12-29 Bridgestone Firestone Tech Pneumatico anti-statico.
US6523585B1 (en) 1997-03-18 2003-02-25 Bridgestone Corporation Antistatic tire
US5872171A (en) * 1997-04-10 1999-02-16 Bridgestone/Firestone, Inc. Silica containing tire compositions for suppression of static charge accumulation
JPH11240312A (ja) 1997-08-04 1999-09-07 Bridgestone Corp 空気入りタイヤ
JPH11240313A (ja) * 1997-12-16 1999-09-07 Bridgestone Corp 導電コーティングを塗布された空気入りタイヤ
KR20000020005A (ko) * 1998-09-17 2000-04-15 홍건희 실리카 타이어의 정전기 방지구조
US6399692B2 (en) 1999-05-06 2002-06-04 Bridgestone Corporation Electrical conductivity of silica-filled rubber compositions using alkali metal salts dissolved in poly (alkylene oxide) compounds
KR100505120B1 (ko) * 1999-11-30 2005-07-29 한국타이어 주식회사 타이어 트레드의 보강층 도포장치
KR20010096800A (ko) * 2000-04-14 2001-11-08 신형인 타이어의 정전기 방출성능을 개선한 외부 도포제 조성물및 이의 도포방법
US7029544B2 (en) 2000-09-15 2006-04-18 Bridgestone Firestone North American Tire, Llc Conductive pathways in tire treads for reduced static charge buildup
WO2002022382A1 (fr) * 2000-09-15 2002-03-21 Bridgestone/Firestone North American Tire, Llc Chemins conducteurs dans les bandes de roulements de pneus permettant de reduire l'accumulation de charges electrostatiques
JP4673486B2 (ja) * 2001-01-29 2011-04-20 住友ゴム工業株式会社 空気入りタイヤの製造方法、及びそれによって製造された空気入りタイヤ
KR20030062752A (ko) * 2002-01-18 2003-07-28 금호산업주식회사 전도성 스프레이 조성물 및 그 응용
DE102004026317A1 (de) * 2004-05-26 2005-12-15 Rhein-Chemie Rheinau Gmbh Verfahren zur Herstellung von Kautschukmischungen
KR100635607B1 (ko) 2005-06-22 2006-10-18 금호타이어 주식회사 타이어 트레드 고무조성물
KR100726867B1 (ko) * 2006-06-09 2007-06-14 금호타이어 주식회사 승용차 타이어 트레드 고무조성물
KR100726866B1 (ko) * 2006-06-09 2007-06-14 금호타이어 주식회사 트럭 및 버스 타이어 트레드 고무조성물
DE602007004044D1 (de) 2006-08-23 2010-02-11 Sumitomo Rubber Ind Gummizusammensetzung für eine Seitenwand und Gummizusammensetzung für einen Clinch-Apex sowie daraus hergestellter Reifen
JP5259332B2 (ja) 2007-10-25 2013-08-07 東洋ゴム工業株式会社 空気入りタイヤ
JP5259337B2 (ja) 2007-11-19 2013-08-07 東洋ゴム工業株式会社 空気入りタイヤ
CA2882515C (fr) 2012-08-31 2016-10-18 Soucy Techno Inc. Compositions de caoutchouc renforcees de fibres et structures filamentaires nanometriques, et leurs utilisations
JP2016523758A (ja) * 2013-06-10 2016-08-12 カンパニー ジェネラレ デ エスタブリシュメンツ ミシュラン 改良されたトレッドを含むタイヤ
WO2015054779A1 (fr) 2013-10-18 2015-04-23 Soucy Techno Inc. Compositions de caoutchouc et leurs utilisations
WO2015089647A1 (fr) 2013-12-19 2015-06-25 Soucy Techno Inc. Compositions de caoutchouc et leurs utilisations
ITUB20154204A1 (it) * 2015-10-07 2017-04-07 Bridgestone Corp Pneumatico con migliorata resistenza alla degradazione termica
DE102019208750A1 (de) 2019-06-17 2020-12-17 Continental Reifen Deutschland Gmbh Verfahren zur Herstellung eines Fahrzeugluftreifens, Vorrichtung zum Ausformen eines zwei Wingkomponenten und eine Ableitkomponente umfassenden Kautschukprofils und Verwendung der Vorrichtung sowie Fahrzeugluftreifen

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR793507A (fr) * 1935-08-05 1936-01-27 Dunlop Sa Perfectionnements apportés aux bandages destinés aux avions ou aux véhicules de toute nature
GB551657A (en) * 1940-12-19 1943-03-04 Firestone Tire & Rubber Co Improvements in or relating to rubber tires
FR1449597A (fr) * 1964-07-21 1966-05-06 Composition élastomère conductrice de l'électricité à base de latex notamment pour couvre-chaussures ou analogues
CH597008A5 (en) * 1977-02-23 1978-03-31 Nicolas Aeschmann Pneumatic tyre for mounting on metal rim of vehicle wheel
US4329265A (en) 1980-03-31 1982-05-11 The B. F. Goodrich Company Outside tire paint
US4857397A (en) 1988-04-08 1989-08-15 The Goodyear Tire & Rubber Company Tire coating composition and use for curing tires
JP2862563B2 (ja) * 1989-06-05 1999-03-03 東洋ゴム工業株式会社 キヤツプベース構造のタイヤ
FR2673187B1 (fr) * 1991-02-25 1994-07-01 Michelin & Cie Composition de caoutchouc et enveloppes de pneumatiques a base de ladite composition.
IT1264990B1 (it) * 1993-12-14 1996-10-17 Pirelli Pneumatico antistatico con mescole a basso tenore di nero di carbonio
GB9409453D0 (en) * 1994-05-12 1994-06-29 Sumitomo Rubber Ind tyre tread and tyres incorporating them

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KR100348228B1 (ko) 2002-12-02
EP0705722A1 (fr) 1996-04-10
JP3542420B2 (ja) 2004-07-14
ES2126207T3 (es) 1999-03-16
DE69506207T2 (de) 1999-06-02
TR199501095A2 (tr) 1996-06-21
KR960010281A (ko) 1996-04-20
DE69506207D1 (de) 1999-01-07
BR9503945A (pt) 1996-09-24
AU714173B2 (en) 1999-12-23
CA2138726A1 (fr) 1996-03-14
AU3035195A (en) 1996-03-28
JPH08120120A (ja) 1996-05-14
ZA957282B (en) 1996-04-04

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